1. Field of the Invention
This invention relates to rowing shell rigging, and to a manually adjustable oarlock pin which supports the oarlock and provides a manual adjustment means for oarlock height adjustment for proper fit of the oar to the rower and rowing conditions.
2. Description of Prior Art
Rowing shells, consisting primarily of rowing boats and sculling boats, are moved through the water by oars. The oars transmit the power of the rower, drawing on strength and proper motions primarily from legs, arms, and back. The speed of the shell is determined by strength, technique, and the efficiency of the transmission of the rower's power through the oar to the water.
Among other things, the transmission of the rower's power is dependent on the relationship of the oar to the rower's body and the surface of the water. This relationship or geometry is determined by, among other things, the inboard and outboard lengths of the oar, stern and lateral pitch, and the height of the oarlock relative to the water. It is generally considered most efficient if, at the finish of the stroke, with the boat "set," the butt of the oar handle comes to a point an inch or two above the xiphoid process, which is the bottom of the rower's sternum. For that to happen, the fulcrum for the oar, the oarlock, must be at the correct height for the individual rower in his or her seat, for the particular boat. Additionally, the vertical angle of the oarlock, which controls the pitch of the blade of the oar is important and dependent on the rower's skill, wind and water conditions.
Various means have been suggested for improving the adjustability or efficiency of the operation of boats that are powered by rowers. See, generally, U.S. Pat. Nos. 4,889,509; 5,324,218; 5,474,008; 4,516,941; and 3,898,950. These patents do not, however, disclose the use of oarlock pins which may be readily adjusted in the water so as to accommodate the variations in the rower's size, weight, crew size, rower's position in the boat and other factors, such as water conditions.
In racing shells, the oarlock, which supports the oar, pivots on an oarlock pin which is supported by a rigger attached to the gunwale of the shell. The rigger and oarlock are designed to allow the oar to move as follows during each stroke: (a) to rotate about the longitudinal axis of the oarlock pin (allowing the oar to sweep through an arc which lies in an essentially horizontal plane); (b) to rotate about an axis which is perpendicular to the longitudinal axis of the oarlock pin (allowing the oar to sweep through an arc which lies in an essentially vertical plane); and (c) to rotate about the oar's own longitudinal axis (allowing the blade of the oar to be "feathered" or "squared" as necessary throughout the stroke).
Generally, the rigging which includes the rigger, oarlock pin, and oar, is adjustable to accommodate the difference in size and weight of rowers, different rowing techniques and different rowing conditions. In particular, the rigger and oarlock pin are designed to allow the oarlock to be adjusted in height above the water and distance from the centerline of the shell. The vertical angle of the pin is frequently also adjustable to facilitate adjusting the angle of the oarlock, which affects the "pitch" of the blade of the oar relative to the surface of the water.
The design and construction of most rigging is such that adjusting one aspect of the geometry of the rigging, like the height of the oarlock, requires a relatively complex sequence of adjustments to one or more of the rigger's structural elements. Sometimes, portions of the rigging must be partially or fully disassembled then reassembled to make an adjustment to the height of the oarlock. These adjustments usually require simple hand tools. Frequently, adjusting the height of the oarlock is a trial and error process until the right height is found for each individual rower, boat, crew weight and water condition. As a result of the difficulty in making such adjustments, they are normally made on land prior to placing the rowing shell in the water, or they are not made at all because it is not practical to make such adjustments each time a rower switches boats or seats in a boat. If the oarlock height is not properly adjusted for each individual rower, the efficiency of the crew and maximum sustainable speed of the rowing shell are reduced.
A primary concern for rowers of shells is adjusting the height of the oarlock so the hand on the inboard section of the oar moves through the proper plane while the blade of the oar moves through the water at the proper depth during the drive. Currently, adjusting the oarlock height on most shells is relatively complex and may require the use of tools, such as wrenches. See, generally, U.S. Pat. Nos. 4,352,667 and 4,411,214. One either adds or removes spacers, and loosen nuts and bolts and moves the oarlock pin, which supports the oarlock and permits it to rotate as needed, up or down through threads in the rigger assembly.
Prior art oarlock pins typically have one or more of the following disadvantages.
In prior art practices, it is necessary to adjust the oarlock height before the shell is placed on the water. This is because the position of the rower in the shell relative to the oarlock and oarlock pin, and the relative instability of rowing shells, makes it very difficult and often impossible for the rower to make any oarlock adjustments, except under emergency conditions. Usually, if oarlock height adjustments are necessary after the shell is placed on the water, a coaching launch is positioned next to the shell and the adjustments are made by an individual from the launch. This is very difficult and inconvenient for the shell crew and the coach. In addition, there is a risk that the rowing shell will be damaged by the launch as the two boats pitch and roll in the water in response to wind and waves. This can be a very difficult and time-consuming activity.
Currently oarlock height adjustments requite using hand tools such as pliers, wrenches, screwdrivers or hex wrenches. Some types of shell rigging require partial disassembly and reassembly to make oarlock height adjustments.
Some current methods of oarlock height adjustment adversely affect other aspects of rigger geometry such as blade pitch. This usually requires readjustment of other aspects of rigger geometry after the height has been modified.
As the rower is not normally in the shell and the shell is not normally on the water when oarlock height is adjusted, measurements are often made between the oarlock and some reference point such as the rower's seat to help estimate the adequacy of adjustments. This is at best inaccurate because it does not consider such factors as the depth at which the shell rides in the water due to crew weight, for example.
A change in crew weight by switching crew positions or substituting rowers results in a change in the shell trim or how deep the shell rides in the water. This affects hand levels and may require oarlock height adjustments. The need for or magnitude of oarlock height adjustments will depend on the magnitude of the change in crew weight.
Some shells are rowed by a crew, each of a different physical size making it necessary to adjust the height of each oarlock to suit the needs of each individual rower. Oarlock height adjustments are difficult enough that they are often not made. Instead, the rower is forced to adjust his rowing technique to accommodate the improper oarlock height. This forces the rower to assume a less than optimal posture in the shell.
There remains, therefore, a very real and substantial need for an effective means for manually adjusting oarlock pin height while a boat is in the water in order to provide for efficient use of the power generated by the rower.